A great variety of sprinklers are known in the art. Generally sprinklers include a large number of interconnected mechanical parts, at least some of which are in contact with water during operation. As a result, the impurities in the water tend to collect and eventually interfere with the proper operation of the sprinkler.
Various sprinkler designs have been proposed in which at least some of the mechanical parts are isolated from the water. Sprinklers designed in this manner are generally relatively complicated and expensive to manufacture.
U.S. Pat. No. 2,909,327 issued to Li discloses a lawn sprinkler that has a rotatable nozzle. A turbine causes wheels to move in guide slots, which allows the nozzle to be shifted and produce a spray pattern. In one embodiment, the wheels are magnetic so as to ensure their engagement with the sides of the slots.
U.S. Pat. No. 4,920,465 issue to Sargent discloses a fountain which has a lamp for illuminating the fountain. The fountain receives water which is under pressure and uses it to drive a turbine. The turbine is magnetically coupled to drive a generator which is located in a watertight envelope. The electricity generated by the generator is used to light the lamp.
U.S. Pat. No. 4,850,821 issued to Sakai discloses a multiple pump system driven by an electric motor with an intermediate magnetic coupling.
U.S. Pat. No. 4,320,927 issued to Sertich discloses a dental drill in which an air driven turbine is used to drive a dental drill. Magnets are used to stabilize the shaft of the drill against axial and transverse-plane movement.